A variable supply, (2.3-2.7)GHz linear power amplifier module for IEEE 802.16e and LTE applications using E-mode pHEMT technology

This paper describes the design and realization of a linear power amplifier for the IEEE 802.16e and UMTS LTE applications operating at the (2.3-2.7)GHz band. The power amplifier comprises a MMIC that uses a proprietary 0.25um enhancement-mode pHEMT technology with integrated output matching inside the module. When tested using a 10MHz bandwidth IEEE802.16e signal with 64-QAM modulation, the amplifier exhibits a linear power output of (23 -24)dBm across the full (2.3-2.7)GHz band with less than 2.5% EVM on a single 3.3V supply while at least 26dBm is typically available with a 5V supply. Efficiency is typically (15-17)% with this supply range. A 20dB bypass gain attenuator that is activated by a CMOS-compatible voltage pin is included on-chip. Output power detection is achieved by the use of an on-chip power detector and a bias shutdown voltage shuts down the complete amplifier. The complete module is packaged in a molded chip-on-board (MCOB) 5mm x 5mm module.